Q: What is the operation of the exhaust Camshaft Position (CMP) sensor?
A: The Camshaft Position (CMP) sensor of the exhaust is similar to that of the Crankshaft Position Sensor because it also generates signal pulses four times in every revolution in a four-cylinder engine or five times in a five-cylinder engine. Additionally, there is an intake CMP sensor for the five cylinders engines which produces one pulse per camshaft revolution. LH9 V8 engines with VVT (variable valve timing) do not require CMP sensors. On LH8 engine, it is located at the front of the timing chain cover and some models will require removal of the water pump to replace this sensor. To take out the sensor, remove its electrical connector from it which is found at the front right corner of inline engines' cylinder head. There are some components on these engines that are exclusive to only a few models that have a 5-cylinder engine-such as mechanical throttle body, integrated EGR and CMP Sensor for Intake Cam, etc. The camshaft position sensor can be removed by unscrewing its retaining bolt and pulling it away from the head. The installation process is simply the reverse of removing it. However, make sure to fit a new O-ring into the fitting hole prior to installing it. Lastly, lubricate this O-ring using diesel fuel or motor oil before assembly.